PolyProwess
This is a budget friendly PolyTyrant/PolyHorror deck aiming to polymorph twice before bouncing all opponents' permanents and generating huge prowess threats, thus winning through board control and combat damage. Narset, Enlightened Exile's ability to copy a Polymorph effect after it was cast in the first main phase enables us to put both Tidespout Tyrant and Hullbreaker Horror onto the battlefield the same turn, leading to some ridiculous interactions.
The Basics
Since we are trying to Polymorph, we can't run any creature spells we don't want to hit from casting that spell. Thus, our deck only runs Tidespout Tyrant and Hullbreaker Horror as creatures in the deck, and Narset, Enlightened Exile in the command zone. Instead, we run noncreature spells that create tokens for us to sacrifice to dig for our polymorph targets.
If we get both our polymorph targets onto the battlefield and have access to two permanent spells that are mana neutral together, for instance Mishra's Bauble and Urza's Bauble since they are both free to cast, we can both create a loop of casting these spells interchangeably and bouncing every permanent we want to remove from the battlefield.
Casting two mana neutral spells interchangeably will also generate an absurd amount of prowess triggers for all our creatures and a really big storm count (likely an infinite amount of both).
If our opponents have no permanents and we have infinitely big threats, we will obviously win the game.
Specifics
For a deeper look into the deck I will first present an example of a game and then go through ways to find the interactions shown.
Example Game
To illustrate what a game might look like playing this deck, I'll give an example. This example is a very good game for the deck, especially since all kinds of interaction is ignored as we do things over a large number of turns. It is not an absurd dream scenario though, and a game when opponents don't interact might well look like this. The kind of turn shown as turn six in the example seems somewhat reliable to get to around turn 8-10 with the deck as of current playtesting.
- Staring hand containing Furycalm Snarl, Mountain, Adarkar Wastes, Dragon Fodder, Izzet Signet, Depopulate and Transmogrify.
- Turn One: Draw Paradise Mantle. Play Furycalm Snarl tapped.
- Turn Two: Draw Generous Gift. Play Mountain and Izzet Signet.
- Turn Three: Draw Plains. Play Plains and Narset, Enlightened Exile.
- Turn Four: Draw Reckless Impulse. Play Dragon Fodder to create two Goblins, trigger prowess. Play Reckless Impulse, exiling Crash Through and Mishra's Bauble, trigger prowess. Attack with Narset, Enlightened Exile exiling and copying Dragon Fodder. Cast the copy to create two Goblins, trigger prowess. Be chump blocked.
- Turn Five: Draw Idyllic Beachfront. Play Transmogrify exiling a Goblin to find Tidespout Tyrant, trigger prowess. Play Mishra's Bauble, trigger prowess, trigger Tidespout Tyrant and bounce an opponents land. Play Paradise Mantle, trigger prowess, trigger Tidespout Tyrant and bounce Mishra's Bauble. Demonstrate a loop of playing bauble and mantle to bounce each other infinitely, thus triggering prowess an infinite number of times. End loop with Paradise Mantle in hand. Attack with a 1,000,003 power Narset, Enilghted Exile and three 1,000,001 power Goblins. Exile and copy Transmogrify. Cast the copy to exile a Goblin and find Hullbreaker Horror, trigger Tidespout Tyrant to bounce Mishra's Bauble, trigger prowess. Be chump blocked.
- Turn Six: Draw Dovin, Grand Arbiter. Play Mishra's Bauble, triggering prowess and both Hullbreaker Horror and Tidespout Tyrant to bounce two of an opponent's permanents. Play Paradise Mantle, triggering prowess and both Hullbreaker Horror and Tidespout Tyrant to bounce Mishra's Bauble and one of an opponent's permanents. Demonstrate the loop again, generating infinite prowess triggers and triggering both Hullbreaker Horror and Tidespout Tyrant an infinite number of times, thus allowing you to bounce all opponents' permanents. Decline Hullbreaker Horror's trigger once opponents are out of permanents if Narset, Enilghted Exile and two Goblins are not yet lethal. Attack for lethal.
Tool Kit
In order to get our combo kill of we need tokens, polymorph effects and mana neutral spell combinations.
We get tokens to sacrifice/exile through sources such as Forbidden Friendship, Ral's Reinforcements, Saheeli, Sublime Artificer, Thopter Spy Network and Elspeth, Sun's Champion. At least two tokens quickly is great, but in grindier games slower options might be better in the long run.
We run four different polymorph effects, mainly since we don't have any tutors. Chaos Mutation, Divergent Transformations, Polymorph and Transmogrify
For mana neutral spell casting, we have our main route though casting spells with a mana cost of zero. In the deck, these are Mishra's Bauble, Urza's Bauble, Tormod's Crypt, Paradise Mantle and Orochi Hatchery. Additionally, Sol Ring is a mana positive spell. This means that Sol Ring will generate infinite mana with any of the zero mana spells, and will create a mana neutral pair with any two mana mana rock that generates a mana the turn it enters the battlefield. For example; Sol Ring generates two mana to cast Talisman of Conviction which generates one mana to cast Sol Ring. (A signet needs one floating mana at the start of the combo but will keep regererating that floating mana throughout.)
Backup Plan
If we cannot combo, this deck functions very well simply by interacting and beating down. We generate a lot of tokens and those tokens can reliably win us games since they all have prowess if we just trust them to. Simply interact and play the deck like any mid power casual deck would play!
